using StellaOps.Router.Transport.InMemory;
using Xunit;

namespace StellaOps.Router.Transport.InMemory.Tests;

public class InMemoryConnectionRegistryTests
{
    [Fact]
    public void CreateChannel_CreatesNewChannel()
    {
        // Arrange
        using var registry = new InMemoryConnectionRegistry();

        // Act
        var channel = registry.CreateChannel("conn-1");

        // Assert
        Assert.NotNull(channel);
        Assert.Equal("conn-1", channel.ConnectionId);
        Assert.Equal(1, registry.Count);
    }

    [Fact]
    public void CreateChannel_ThrowsIfDuplicate()
    {
        // Arrange
        using var registry = new InMemoryConnectionRegistry();
        registry.CreateChannel("conn-1");

        // Act & Assert
        Assert.Throws<InvalidOperationException>(() => registry.CreateChannel("conn-1"));
    }

    [Fact]
    public void GetChannel_ReturnsNullForUnknown()
    {
        // Arrange
        using var registry = new InMemoryConnectionRegistry();

        // Act
        var channel = registry.GetChannel("unknown");

        // Assert
        Assert.Null(channel);
    }

    [Fact]
    public void GetChannel_ReturnsExistingChannel()
    {
        // Arrange
        using var registry = new InMemoryConnectionRegistry();
        var created = registry.CreateChannel("conn-1");

        // Act
        var retrieved = registry.GetChannel("conn-1");

        // Assert
        Assert.Same(created, retrieved);
    }

    [Fact]
    public void RemoveChannel_RemovesAndDisposes()
    {
        // Arrange
        using var registry = new InMemoryConnectionRegistry();
        var channel = registry.CreateChannel("conn-1");

        // Act
        var removed = registry.RemoveChannel("conn-1");

        // Assert
        Assert.True(removed);
        Assert.Equal(0, registry.Count);
        Assert.True(channel.LifetimeToken.IsCancellationRequested);
    }

    [Fact]
    public void RemoveChannel_ReturnsFalseForUnknown()
    {
        // Arrange
        using var registry = new InMemoryConnectionRegistry();

        // Act
        var removed = registry.RemoveChannel("unknown");

        // Assert
        Assert.False(removed);
    }

    [Fact]
    public void Dispose_DisposesAllChannels()
    {
        // Arrange
        var registry = new InMemoryConnectionRegistry();
        var channel1 = registry.CreateChannel("conn-1");
        var channel2 = registry.CreateChannel("conn-2");

        // Act
        registry.Dispose();

        // Assert
        Assert.True(channel1.LifetimeToken.IsCancellationRequested);
        Assert.True(channel2.LifetimeToken.IsCancellationRequested);
        Assert.Equal(0, registry.Count);
    }
}